What is the definition of Congenital Muscular Dystrophy Type 1A?
Congenital muscular dystrophy type 1A (MDC1A) belongs to a group of neuromuscular disorders that beings at birth or infancy and is characterized mainly by hypotonia, muscle weakness and muscle wasting. Other signs and symptoms include rigidity of the spine; scoliosis; and delayed, limited motor development, with most individuals needing assistive devices for mobility. Respiratory problems, feeding disorders and seizures may also occur. With time, affected individuals may develop an elongated face and ophthalmoplegia disorders (paralysis or weakness in muscles of the eye). Intellectual development is typically normal. The prognosis is poor, as many affected children do not reach adolescence. It is caused by mutations in the LAMA2 gene and is inherited in an autosomal recessive manner. Treatment is generally symptomatic and includes a multidisciplinary approach.
What are the alternative names for Congenital Muscular Dystrophy Type 1A?
- Merosin-negative congenital muscular dystrophy
- Merosin-deficient congenital muscular dystrophy
- Muscular dystrophy, congenital, merosin-deficient
- Laminin alpha-2 deficiency
- LAMA2-related muscular dystrophy
What are the symptoms for Congenital Muscular Dystrophy Type 1A?
Infants with congenital muscular dystrophy type 1A (MDC1A) typically have poor muscle tone (hypotonia) and muscle weakness at birth. Within weeks after birth, some affected infants may have feeding and respiratory difficulties. Motor development is often delayed and limited. Most affected infants can sit unsupported and some can stand without assistance. Only a few children with MDC1A are eventually able to walk unassisted. Additional signs and symptoms that affected individuals may experience include joint contractures (stiff or "frozen" joints), congenital hip dislocation, scoliosis, and ophthalmoplegia (paralysis or weakness in the muscles of the eye). Affected children may also develop an elongated face. Approximately 20-30% experience seizures. The majority of affected individuals have normal intellectual abilities. The prognosis of this condition is poor, as many affected children do not reach adolescence.Although most individuals affected with MDC1A have complete deficiency of the merosin protein, a few individuals have only a partial deficiency. Among individuals with a partial deficiency, the severity and age of onset varies greatly. One study reported that approximately 12% of individuals have later onset, slowly progressive weakness.